Planograph co



H. S. AND M. D. DAVIS.

APPARATUS FOR T HE ESTIMATION 0F VAPOR PRESSURES.

APPLlcATmN FILED 1AN.3|.1919.

1,3 l 8, 3 2 Patented Oct. 14, 1919.

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TMB COLUMBIA FLANoGR/wn cn., WASHINGTDN, D. C.

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HAROLD SIMMONDS DAVIS AND MARY DAVIDSONVDAVIS, OF PITTSBURGH, PENN- i SYLVANIA. l

APPARATTS FOR THE- ESTIMATION 0F VAPOR-PRESSURES.

Specification of Letters Patent.

Patented Oct. 14, 191.9.

Application led January 31, 1919. Serial No. 274,228.

To all whom t may concerns Be it known that we, HAROLD S. DAVIS and MARY D. DAVIS, residing at Pittsburgh, Allegheny county, Pennsylvania, have invented a new and useful Improvement in Apparatus for the Estimation of Vapor- Pressures, of which the following is a full, clear, and eXact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a Y front elevation partly broken away of one form of apparatus embodying our invention; and Y Fig. 2 is a section on the line vII--II of Fig. 1. Y l

Our invention. has relation to apparatus for use in the estimation of vapor pressures. It is designed to provide a simple and convenient form of apparatus which can ybe used for the purpose of carrying out the method of quantitative estimation of vvapors in gases described and claimed in our Patent No. 1,272,922, dated July 16, 1918, as well as for other purposes, some of which are hereinafter referred to.

The natureV of the present invention will be best understood by reference to the accompanying drawing, inv which we have shown the preferred form thereof and which will now be described, it being premised, however, that the particular form of apparatus which we have illustrated may be widely varied in detail, without departing from the spirit and scope of our inven tion as setforth in the appended claims.

In this drawing, thev numerals 2 and. 3 designateV two similar necked flasks, preferably of labout 150 tol 300 cubic centimeters capacity each. These flasks are connected by a manometer'tube 4, whose ends 4are sealed into the necks of the lrespective flasks, as indicated at 5. The two flasks are preferably located relatively close together, so as to permit of their immersion, when necessary, in a constant temperatureA bath, and the manometer tube ,is preferably so shaped and arranged as to be offset from the flasks in a manner to enable itV to stand outside of the bath when the flasks are immersed. Each of the flasks is tightly closed, preferably by va ground glass stopper 6, which is capable of making an air-tight joint. Each branch of the manometer tube is preferably provided with the stop cock 7 bv means of which the pressures in the two flasks may be brought to atmospheric pressure andV thus equalized. One ofthe branches is also preferably provided with a second stop cock S, to facilitate the evacuation of the flask.

Each of the Stoppers 6 is shown as having therein a tube 9, aassing vertically there-v through, with a metal rod 10 extending slidably through such tube. At their lower ends, these rods project downwardly into the respective flasks 2, and 3, and attached to the lower end of each rod is a small sealed glass bulb 11, which is preferably formed with a thin bottom, so as to be readily breakable, and which contains sealed up within it, some of the substances whose vapor is to be determined. The upper end portion of each rod has secured thereto a push member 12, which seats withinl the upper end portion of a piece of flexible rubber tube 13, whose lower end'seats over the upper end of the tube 9.

The rubber tube makes a tight fit at its end portions, and the joints may be made tight in any suitable manner, vas by the use of vacuum grease and wire wrapping, such as indicated at 14.

The manometer tube may be filled with mercury or any suitable liquid, and is provided with a scale 15, upon which any difference in pressure in the two flasks may be directly read. W'hen mercury is used for the manometer liquid, one millimeter is a 'convenient size for the bore of the manometer tube. y

The actual dimensions of any parts of the apparatus may be varied within wide limits; but in order to obtain accurate results quickly, it is essential that when the sealed bulb is broken in the bottom of the flask, its vapor should be lable to quickly penetrate throughout the interior of the iask. Therefore, local pockets in the interior surfaces in which the vapor would diuse but slowly should be avoided, and all connecting tubes should have .a small volume compared with the total volume of the flasks. y

The'sealedbulbsmay be readily broken by pushing down the upper end of the metal rods 10, the rubber tubes 13 yielding enough to permit the bulbs with their thin bottoms to be forced into breaking contact with the bottom wall of the flask.

One method of using the apparatus for the quantitative estimation of vapors in .Y The-pressuresin the two flasks are equalized at the highest temperature by opening and closing the stop cocks, to thereby bring the pressure in each flask to atmospheric. The bulb containing the substance in question is then brokenA in'fthe flask at one' side. Then the pressure is fully developed, it is 'l read from the nianometer. The apparatus start with the highest temperature, sol that` tinuously decreasing,

is then brought 'to they next highest temperature. i The air' pressures' will necessarily Vcompensate and the vapor pressure. of the substances at this temperature can be readl l from`r the inanometer.y

The operations are repeated for asmany temperatures as desired. Itis preferable to the total pressures in the flasks: willbe con'- theieby lessening the danger or" leakage.

(3) F or the measure of the vapor pressure from the solution of a volatile substance in a non-volatilesubstance.

This may bey obtained by having lin the bottoni 'of theilask some of the non-volatile substance and breaking into it a bulb con-v tainingthe volatile substance. For instance,

the vapor pressure of benzene froni'washl 'oil can be Vfound by breaking the bulb e011.-

taining a'known weight of benzene into a known weight of wash oil in onev flask.

It will be noted that other gases than air', may be used in the flasks and that the` pressures, may be regulated in various ways. Y

" We claim:` f

l. Apparatus for the estimation of vapor pressures vcomprising two similar flasksv con- 'v nested by afmano'meter, and a fragile containerv adapted @to be inserted into one y'of' said v flasks, and a carrier for supporting the conn tainer' lin theflask having nieanswhereby said container maybe broken withinzsaid Y flask, substantially as described. 2.' Apparatus for the ,estimation of vapor.

pressures, comprising two similar flasks connected by amanometer, and'having openings -in their necks, and removable closures o for said openings which provide means y`.for

Copies f'tkiis patent nia'ybe obtainedffor live` cents each, by addressingltlie Commissioner 01..' Patentggf Y ble'memberfforming a seal Aforthe joint.

, scribed.

introducing fragile containers "into the. flasks, said closures having means whereby the Centaliere ,may .be breken within the flasks, substantially as described.

Y 3. Apparatus for the estimation of vapor pressures comprisingitwoy flasks having necks connected by a manometer tube and having reinovabletight-fitting stoppers, a vertically movable member seated in each of said stoppers and adapted'to support a fragile`co1itainer at its lower end portion, and means for sealing the flasks Vagainst thefentranee of air pastKV said members, substantially de` scribed. l

4. Apparatus for the estimation of 'vapor' pressures, kcomprising 'two flasks, a manom eter connecting saidliasks, andhaving meansfor equalizing the pressures therein,'saidV flasks having openings, and removable clos sures .for sealing said openings, 'said :losur'esV having mean-s wliereby'a fragile container mayjbe broken within the flaskswithoutvre tially as described j ,A

5. Apparatus for the estirfiation'A ofvaglor-` pressures, comprising two sealed'flasks connected by a manometfer tube, said Ytube 'being offset from the flasks, and removable clofi suies for said flasks,` ^said closures 'luivingwV means whereby container Vmay' be intro! duced v'into iand broken withinfthefiasks,i Y substantially as.ide'scribed j 6; Apparatus for the estimation ofjvapor 1 pressures, comprising two sealedllasks. conl "9.5r ingmeans for evaciiatingtlie flasks and; also l nested by a manometertube, said tubeQhav- 'niovingor unsealin'gthe closures, su b st an -v for equalizing the pressures thereinpandre:

movable closures for saidQ flasks, said elo; Q sures liavingmeans wherebya fragile sealed f t t, 10Q Within the iaSkSf, ,Substantially as described-@ 7 Apparatus ,for theestiinationof vap0r pressures comprises. two esks-m1'1nectd by a manometertube, each of said'iaskshay-f; ins e tight-fitting.remrebleistrpea @tube extendingv through the stopper,al'vertically Y container may be introduced into andjvbrokeinmovable rod .seated in 'tlieftulo-e," andlaffle'xitween the rod and' tube, Substantiallyasd 8. Apparatus the lestiniation of pressures kcomprisingtwo flaskscqnne'ctedlby I a manometer,*means'foriequalizing theA pres-;

sures withinthe flasks, and a vertically movf able container carrier extending jinto'eaclr fla-Sk substantially y'as described' In testimony whereof, `we have hereunto i 'setourhandsm V HAROLD siMMoNDs Davis; j

i 'i MARY; DeVlDSONDAVis4y] Washington, '.D.;'G. 

